Tire-pump.



L. A. ANDREWS.

TIRE PUMP. APPLICATION FILED ocr. 26, 1914.

Patented Apr. 1916.

11i/veg@ W ./ndfrews Louis RENE-EEE srnrEs EaEENtr oEEipE.

Louis A. aNEEEwS, or NEWTON UPEEE Earns, NassacHjUsErEs.

TIRE-PUMP.

T0 aZ-Z whom it may concern Be it 'lznown that I, LOUIS A. ANDREWS, a subject of the King of Italy, and a resident of Newton Upper Falls, in the county of Middlesex and Commonwealth of Massachusetts, have invented certain'new and useful improvements in Tire-Pumps, of which the following'is a full, clear, and exact specification. y

This invention relates to that type of air pumps especially designed for inflating pneumatic tires, wherein the piston is provided with a cupped disk of leather adapted by the engagement of its flanged edges against the interior of the pump-cylinder. to make'thepiston air-tight during its down stroke. The chief diliiculty with this is that after atime the cupped edges of the leather become permanently flexed inward and so fail to contact with the interior of the cylinder, consequently failing to be air-tight and rendering the pump useless,

The purpose of this invention is primarily i. the effecting of means for preventing above recited inward iexing of the leather washer'. To accomplish this, I provide at the end of the cylinder an expander adapted temporarily to press outward the cupped edges of the leather washer, and so to insure their contact with the cylinder.

Referring to the drawings forming part of this specication, Figure 1 is aside sectional view, substantially full size, of a hand pump embodying the primary feature of my improvements. Fig. 2 is a similar section, but on a smaller scale, of a double-acting pump made in accordance with my invention. Fig. Sfisa similar section of a twocylinder pump embodying my improvements. Fig. YIl is a detail sectional view of the double acting valve used in connection with the double acting pump shown in Fig. 2. 'Fig 5 is a Sectional detail view ofthe ball valve used in the construction disclosed in Fig. 3.

In the simplest vform of *the -invention shown in Fig. l, the cylinder 1 is expanded at its lower end to compose an annular recess 2 of larger diameter than the cylinder, in order to provide a space into which the cupped edges 3 of the washer 4 can be i .forced by the expander.

Centrally within the cylinder `end is located the expander, which preferably consists of a conical ring '5 the smaller diameter of which is less than that which can ever be taken by the cupped Specification of Letters Patent.

a pneumatic tire.

rammen api. a., isis.

Application led October 26, 1914. Serial No. 868,605.

edges 3, while its largest diameter is in excess of that of the interior of the cylinder A1. Consequently, when the piston is pressed down to the lower end of the cylinder, the cupped edge of the washer i is entered by said ring and pressed diametrically outward into the annular space 2 and given a larger diameter than'the interior of lthe cylinder. When, now, the piston is withdrawn, the cupped edge rides up the curved shoulder 6 and is Vcontracted to the diameter of the cylotherwise there would have to be a comparatively sharp V-groove to receive the cupped edge, which would not only injure said edge, but wouldnot insure its air-tight lit against the cylinder; for, as is well known in the construction of metal springs, a body which is not absolutely inelastic must be bent beyond the desired point in order to` remain thereat. Hence the necessity of pressing the cupped edge to a larger diameter than that required.v v

1n Fig. 2 is illustrated a double action pump having the cupped washers 4 facing in opposite directions, and provided with .the expander rings 5'and annular recesses 2 at both ends. The heads 9 are joined by a pipe 10 connected by conduits 11 with the interior of the cylinder 12, and from this pipe runs the usual rubber tube 13 by which the compressed air is delivered to the At the 'juncture of the pipe 10 and the nipple 14 to which the rubber tube is attached, is a chamber 15 containing a ball 16, and both above and below said juncture is a valve seat 17, so that when the air is compressed in one sec tion of the cylinder, said ball is forced intp contact with lthe seat 17 which closes the air from entering the other section, and so a second one 19-of substantially the same length but of considerably less diameter. In this secondary cylinder 19, the expander ring 5 thereof, `and the washer 4 is cupped upward. A conduit 20 opens from the main cylinder l2 tothe secondary cylinder 19, and the compressed air is taken from the top end of the cylinder 19 through a conduitl 21 and rubber tube 13.

'As shown in Fig. 5, the lower end of the piston rod 22 is tubular and provided with a ball valve 23 and seat 24, and above the piston is a radial-.hole 25 opening out into the cylinder 19, in order that the air may pass from beneath to above the piston as the latter descends, but none such can pass as the piston rises.

The operation of this double pump isl as follows: lVhen the handle 26 is pushed downward, the air in the cylinder 12 beneath the piston therein is forced out therefrom into the cylinder 19, passing through the tubular lower end of the piston rod 22 the tubular lower end of the piston rod 22 and the hole 25 into the upper section of the cylinder 19. Since the latter cylinder is materially smaller than the main cylinder, the air is forced on through to the rubber tube 13 and thence -to the tire being inflated. When the handle is raised, the ball valve 23 closes and the air above the piston in the cylinder 19 is also forced through the tube 13 to the tire. Y

In both the double acting pump shown in F ig. 2, and the double pump shown in Fig. 3, the annular recesses 2 cast heads of the cylinders, instead of by and recess 2are at the upper endare made in the expanding the cylinders as set -forth in .\Fig. l. To admit air to the double acting cylinder 12 shown in Fig. 2, a ball-controlled intake`27 is provided at each end'of the cylinder. At the upper end of the cylinder 12 of the pump shown in Fig. 2, and of the cylinder, 19 shown in Fig. 3, the piston rod requires air-tight packing. This is providedby giving the boss 30 a conical recess, and its screw cap 31 a corresponding conical recess. By inserting a. rubber double-cone 32.in each recess of said bosses, and suitably screwing downthereabout the screw cap 31, the rubber packing cones 32 are compressed about the piston rods and alle escape of air about the same is prevented.

What I claim is: i

A pump comprising a. cylinder, a piston therein having a cupped flexible washer, and a conical member located in the end of the cylinder to be engaged by the flexible washer, the space within the cylinder about the conicalmember being larger in diameter than the interior of the cylinder, and the base of the conicalr member being larger in diameter than the interior'of the cupped washer, whereby the washer is expanded largerlhan the cylinder at the end of the pistons stroke and thereby made to tightly fit the same.

In testimony that I claim the foregoingl invention, I have hereunto set my hand this Y 23rd day of October, 1914.

LOUIS A. ANDRFNVS.' i lVitnesses:

A. B. UPHAM, MARGARET N. BALDWIN. 

